金属热黏塑性本构关系的研究进展

金属材料的塑性流动行为依赖于温度和应变率，温度和应变率敏感性是金属材料塑性流动的最重要的本质特性之一，建立合适的热黏塑性本构关系来准确描述金属塑性流动行为的温度和应变率依赖性，是金属材料能被广泛应用的必要前提。为此，对金属热黏塑性本构关系的最新研究进展进行了综述，介绍了常见的几种金属热黏塑性本构关系并进行了详细讨论，给出了各本构关系的优势与不足，最后系统介绍了包含金属塑性流动行为中出现的第三型应变时效、或K-W锁位错结构引起的流动应力随温度变化出现的反常应力峰以及拉压不对称等行为的金属热黏塑性本构关系的研究进展。

Advances in the research of metallic thermo-viscoplastic constitutive relationships

The studies of the plastic flow behaviour of metallic materials show that the plastic deformation process of metallic materials is dependent on temperature and strain rate, so the temperature and strain rate sensitivities are the most important essential properties of plastic deformation of metallic materials. It is therefore necessary to establish appropriate thermo-viscoplastic constitutive relations to accurately describe the temperature and strain rate dependences of the plastic flow behaviour of metals over a wide range of temperatures and strain rates. Advantages and disadvantages of these constitutive relationships are first reviewed in the present paper. With the increasing applications of metallic materials and the emergence of new materials, the 3rd type strain aging, K-W lock induced anomalous stress peak, and tensile-compression asymmetry are often observed in the plastic flow behaviour of metals. Due to the occurrence of those phenomena, the traditional metal thermo-viscoplastic constitutive relations may no longer be applicable. In view of the significant roles played by the 3rd type strain aging, K-W lock dislocation structure-induced anomalous stress peaks, and tensile-compression asymmetry in the plastic flow behaviour of metals, especially in high temperature loading, it is necessary to take those particular phenomena into account in the framework of the thermo-viscoplastic constitutive relationship of metals. Thus, a large variety of constitutive relation, which considers the interaction of strain, temperature and strain rate, has been established to predict the deformation behaviors of metals. In this context, this paper presents a systematic review of the thermo-viscoplastic constitutive relationships of metals, which includes the anomalous stress peaks in the flow stresses with temperature due to the 3rd type strain aging or K-W-locked dislocation structures, and the tensile-compression asymmetry. In addition, the forms of these thermo-viscoplastic constitutive relationship considering the 3rd type strain aging, K-W lock dislocation structure-induced anomalous stress peaks and tensile-compression asymmetry in the flow stress of metals, are discussed and analysed.